Shielded monopolar electrosurgical apparatus

Abstract

The instant invention is a shielded monopolar electrosurgical instrument for use in laparoscopic and the like surgical procedures. The instrument consists of a rigid outer metallic shield which operates as a conductive coaxial shield and is connected to a patient return electrode of an electrosurgical generator. The use of a coaxial shield coupled to the patient return electrode on the outer surface of the instrument eliminates the need for an outer insulative coating. The shield houses a conductive wire positioned through the center of the shield which is coupled to the active lead from the electrosurgical generator. Between the wire and the shield is placed an insulating sleeve. The tip of the instrument is interchangeable and the instrument may be used in conjunction with a form fitting handle providing the surgeon with finger holes in order to apply pressure to the instrument for operation of grasping items when such a tip is employed.

What is claimed is: 
     
       1. An electrosurgical apparatus comprising: a hollow elongated housing constructed from a conductive material and defined by a proximal end and a distal end forming an interior chamber therebetween, said proximal end adapted for releasable coupling to a patient return electrode of an electrosurgical generator; an active electrode disposed within said chamber having a first end adapted for coupling to an active lead on said electrosurgical generator and a second end forming an exposed surgical tool for effecting at a tip of said tool an electrosurgical procedure; a means for electrically isolating said active electrode from said housing; a first handle electrically coupled to said housing and pivotally connected to a second insulated handle for support of said active electrode, said handles operatively associated with said active electrode for controlling longitudinal movement of said surgical tool; wherein said housing is adapted to be at the same potential as said patient return electrode when said housing is connected to the return electrode of the electrosurgical generator and whereby said active electrode is available for electrosurgery procedures and is electrically isolated from said housing. 
     
     
       2. The apparatus according to claim 1 including a means for isolating said second handle from said active electrode. 
     
     
       3. The apparatus according to claim 1 including a rotatable knob coupled to said housing means providing ease of rotation of said surgical tool. 
     
     
       4. An electrosurgical apparatus comprising: a housing defined by a hollow elongated shield of conductive material defined by a proximal end and a distal end forming an interior chamber therebetween; a first handle electrically coupled to said housing and pivotally connected to a second insulated handle; an active electrode disposed within said interior chamber having a first end operatively associated with said first handle and adapted for coupling to an electrosurgical generator with a means for electrically isolating said first handle from said active electrode and a second end of said electrode adapted for coupling to a surgical tool for effecting an electrosurgical procedure at a tip, said second end of said active electrode having a tip body fabricated from a non-conductive material; a sleeve of non-conductive material for electrically isolating said active electrode from said housing, said sleeve positioned within said shield and extending from said proximal end to said distal end; a support formed from said second handle electrically coupled to said housing and pivotally connected to said first handle for support of said active electrode, said second handle having an electrode terminal for coupling to a patient return electrode on an electrosurgical generator and adapted to maintain said second handle and said housing at the same potential as said return electrode.   
     
     
       5. The apparatus according to claim 4, wherein said first handle includes a cavity for receipt of said first end of said active electrode, said cavity having a means for insulating said electrode from a body of said first handle. 
     
     
       6. The apparatus according to claim 5, wherein said first end of said active electrode is releasably secured in said cavity by an inner active lead having a lower end which electrically engages said first end of said active electrode and an upper end adapted to couple to a coaxial cable for connection to the electrosurgical generator. 
     
     
       7. The apparatus according to claim 4, wherein said housing means is releaseably coupled to said first handle including a means for allowing rotation of said housing means in relation to said first handle. 
     
     
       8. The apparatus according to claim 4, wherein said second end of said electrode threadingly engages said distal end of said housing means. 
     
     
       9. The apparatus according to claim 4, wherein said sleeve is constructed from non-conductive tubing. 
     
     
       10. The apparatus according to claim 4, wherein said sleeve is constructed from plastic tubing. 
     
     
       11. The apparatus according to claim 10, wherein said plastic is polyetheretherketone. 
     
     
       12. The apparatus according to claim 4, wherein the connections of the first handle and the second handle may be reversed.